Tufts University professor finds aquifer on campus

Thursday

Mar 25, 2010 at 12:01 AMMar 25, 2010 at 12:16 PM

Grant Garven is boring. Well, not anymore — but he was last summer. In 2009, the Tufts University geology professor spent around $20,000 from research funds to drill three boreholes around the Medford-Somerville campus in order to provide students with an on-site laboratory to study groundwater running through the area.

Nell Escobar Coakley

Grant Garven is boring. Well, not anymore — but he was last summer.

In 2009, the Tufts University geology professor spent around $20,000 from research funds to drill three boreholes around the Medford-Somerville campus in order to provide students with an on-site laboratory to study groundwater running through the area.

“I believe it’s the first university on the East Coast where a professor drilled holes in the ground and got away with it,” Garven said jokingly.

Garven, who also teaches civil and environmental engineering, arrived at Tufts from Johns Hopkins University two years ago and quickly found it difficult to give students a hands-on way to study groundwater. He said to do so usually involved a Saturday field trip out to Cape Cod, where the U.S. Geological Survey has installed several observation wells, and finding transportation for everyone.

That’s when he approached the school’s administration about providing a more convenient alternative.

“They probably thought I was wacky,” Garven said. “But I received great support from John Vik [Tufts’ grounds manager]. He was very enthusiastic. I also got great support from the president, Larry Bacow.”

Garven said Dig Safe came out last summer and checked the university sites, pronouncing the project good to go. Cushing & Sons Drilling of Keene, N.H. dug the wells.

What Garven found was both expected — and unexpected.

“We found what we expected in terms of the geology of the area,” Garven said. “By Powder House, we found Medford Gabbro (a black type of igneous rock) in a vein that runs from there right through Medford.”

Garven said there was something to learn from all the sites and even though it was months ago, data is still being analyzed.

“I really wanted to explore the geology, but I also wanted to learn more about the groundwater,” he said. “We can now test for the pressure of the water, measure it with probes, even put a camera down there and actually see the water.”

And water is exactly what Garven saw in one of the boreholes — but not in the amount he was expecting. At the last site on the campus quad, Garven made a huge discovery about 250 feet down.

“We hit a big supply of water,” he said. “The students started calling it Jumbo’s Aquifer. It was a total surprise. We just didn’t expect that.”

An aquifer is an underground rock formation composed of such materials as sand, soil or gravel that can store groundwater and supply it to wells and springs.

Garven said the find is unusual because the type of hills in which the aquifer rests are torpedo shaped and usually filled with rock and clay left behind by glaciers. This one was filled with gravel.

“The neat thing about hydrology is that until we dig, we might have an idea what’s there, but you never really know,” he said.

Garven said the aquifer is exciting news for Tufts, which dug a 600-foot borehole at Powder House to find a water source to irrigate the fields several years ago. Without much success, the school gave up on the project.

What the school will do with the new find Garven doesn’t know. However, he plans to use this and the other two sites to show his students and others all about the area they live in.

“Kids walk across the campus every day to classes,” he said. “They can see firsthand what’s underground.”

Since the lab has been open, it’s given Garven yet another tool in his teaching arsenal.

“Usually a professor stands at a blackboard and lectures or shows a DVD or an old movie,” he said. “Last fall, they were drilling right here and the students got to see all the action. It was a really valuable and unique opportunity.”

Garven’s still trying to get a sense of how permeable the rocks in the area are to groundwater and the outdoor lab will allow him to set up field experiments. He said his next project is to possibly open up the lab.

“I’d like to share it with the community,” he said. “The goal is to not only set it up for Tufts students and other departments, but students at other schools.”